Depth gauge



April 5, 1949. c, McL, WQRNELL I 2,466,140

DEPTH GAUGE 2 Sheets-Sheet 1 Filed. June 19, 1945 1!] )0 5 5mm y HTTO/F/VEX LJ Q 7v 2 Sheets-Sheet 2 C. N. M L. WORNELL DEPTH GAUGE April 5, 1949.

Fild June 19, 1945 Patented Apr. 5, 1949 DEPTH GAUGE Charles Norman McLeod Wornell, Chessington, England Application June 19, 1945, Serial No. 600,302 In Great Britain June 30, 1944 3 Claims. 1

This invention relates to gauges of the kind having a calibrated rule with which is associated a sliding member.

In such gauges when constructed for taking long measurements the calibrated scale has to be of substantial thickness to provide the necessary rigidity. This reduces the utility of the gauge for other purposes, particularly for measuring the depth of small diameter holes.

The object of the present invention is to provide an improved gauge which will have a suflicient degree of rigidity combined with a rule of relatively small cross sectional dimensions.

According to the present invention an auxiliary member is provided on said sliding member said auxiliary member being disposed parallel to said rule and being of small cross-sectional dimensions relative to said rule. A head or stop may be mounted on said auxiliary member and be adapted to be operatively associated with said calibrated rule for the purpose of making the measurement by the use of said auxiliary member in association with said calibrated rule. The stop may be movable into and out of the path of the calibrated rule and may be removably secured to one end of the auxiliary member. The auxiliary member may pass through the sliding member to which it may be clamped in any desired position. Alternatively, the head or stop may be mounted on the calibrated rule and be adapted to be operatively associated with the auxiliary member.

One form of the invention, applied to a depth gauge, is illustrated in the accompanying drawings, wherein:

Fig. 1 is an elevation;

Fig. 2 is an underneath plan view; and

Figs. 3, 4 and 5 are elevations showing the gauge in various operative positions.

In the form shown the gauge comprises a slid ing member It) provided with a slot H normal to the flat end face l2. A calibrated rule I3 is provided, and the slot H in the sliding member if) is adapted to accurately receive said rule so that the rule may slide therein. The end face 14 of the rule is parallel to the end face l2 of the sliding member. A thumbscrew [5 in the sliding member In is adapted to lock the rule to said sliding member in any relative position. The sliding member is also provided with a second slot or hole I6 adapted to accurately receive an auxiliary member l1, consisting of a rod of substantially smaller cross-sectional dimensions than the rule l3, so that said auxiliary member may slide in said sliding member. The slots H and I6 are parallel to each other, whereby the calibrated rule 13 and the auxiliary member I! are also retained parallel to each other. The end face ill of the auxiliary member is also parallel to the end face 12 of the sliding member and to the end face M of the rule l3. A thtunbscrew IS in the sliding member 10 is adapted to lock the auxiliary member I! to the sliding member in any relative position.

The auxiliary member or rod I1 is provided at its end remote from the end face [8 with a head 20 recessed at 2| to accurately receive and engage the end face 22 of the calibrated rule 13. The relative lengths of the rule [3 and rod l1 and the position of the head 20 with its recess 2| are such that when the end face 22 of the rule l3 abuts the bottom of the recess 2| the end faces 14 and I8, respectively, of the rule l3 and rod H are in one plane parallel to the end face [2 of the sliding member Ill. The end of the rod H is provided with a collar 23, secured thereto by a dowel pin 24; the head 28 is drilled to fit accurately on the rod I! and be rotatable thereon, and a knurled screw-threaded nut 25, engaging a screw thread on the rod 11, is adapted to clamp the said head against the said collar.

When the gauge is to be used to gauge the depth of a hole or recess having a cross section smaller than that of the rule l3, the thumbscrew H! is released from engagement with the rod H, the said rod is slidden in the sliding member It! so as to move the head 20 out of engagement with the rule l3, and the said head is then rotated on the rod ll out of the plane of the rule [3 as shown in Fig. 3. The sliding head in and the rod H are then used in the usual manner to gauge the depth of the hole, the end face is of the rod being projected beyond the end face 12 of the sliding member in the manner shown in Fig. 3. The rod I1 is then looked to the sliding member ID by the thumbscrew IS, in the position obtained. The rule I3 is then moved a suitable distance through the sliding member It, the head 20 is returned into the plane of said rule and the rule is withdrawn through the sliding member until the end face 22 of the rule enters the recess 2| of the head 20 and abuts the bottom of said recess, the relative positions shown in Fig. 4 being obtained. The rule may then be locked, by means of the thumbscrew IE, to the sliding member If), and the depth of the hole being gauged may be read off the calibrations 26 on the rule l3 against a scale 21 on the sliding member ID. The slot H in the sliding member ID is open on the front face of the said member to enable the calibrations to be read, the edges of the open side of the slot being suitably shaped.

In an alternative method of using the gauge, the rule I3 is projected from the sliding member ID to a position illustrated in Fig, 5 with a desired depth indicated by the calibrations 26 against the scale 21, the rule is locked to the member I I] by the thumbscrew I5, the rod I1 is moved through the sliding member I until the end 22 of the rule I3 is engaged in the recess 2! of the head 20 as illustrated in Fig. 4, the rod I1 is locked in position by the thumbscrew I9, the thumbscrew I5 is released, the head is rotated out of the plane of the rule, the rule is withdrawn to the position illustrated in Fig. 3, and the rod I1 is then in position for gauging a recess or hole.

An auxiliary slide 28 is mounted on the callbrated rule I3 and rod I1, and is adapted to be locked to the rule by a thumbscrew 29. A fine screw-threaded rod 30 passes through the slide 28 and through a knurled nut 3| disposed in a slot in the side of the slide 28. The rod 30 is parallel to the rule I3 and rod I1, and the nut 3| is free to rotate in the slide 28, but is restrained against axial movement; rotation of the nut 3! causes the rod 30 to move axialy in the slide 28. The end of the rod 30 is adapted to be inserted in a hole 32 in the sliding head In and be locked therein by a thumbscrew 33. By looking the slide 28 to the rule I3, locking the rod 30 in the sliding member I0, and operating the nut 3|, fine adjustment of the sliding member Ill relative to the rule l3 may be effected, a Vernier scale 21 on the sliding member I0 being utilised.

The rod I1 described constituting the auxiliary 4 member may be varied in form to suit circumstances, but it Will be obvious that whatever form it takes additional rigidity is given to the gauge when the various parts are locked together, and when the end 22 of the rule is located in the recess 2| further additional support is aflorded.

To secure the maximum advantage from the combination of the auxiliary member or rod with the rule the auxiliary member may have a cross section possessing maximum rigidity 0r stillness at right angles to the direction of maximum rigidity or stiffness of the rule.

What I claim and desire to secure by Letters Patent is:

1. A gauge comprising a calibrated rule, a head in which said rule is slidably mounted, the said head having a face disposed in a plane normal to the path of sliding movement of said rule, an auxiliary member also slidably mounted in said head, said auxiliary member being disposed parallel to said rule and being of small crosssectional dimensions relative to said rule, the paths of sliding movement of the said rule and of said auxiliary member in said head being parallel to each other, and a stop member pivotally mounted on said auxiliary member and normally disposed in the path of sliding movement of said rule thereby to abut the same and limit movement of the rule in one direction relative to said auxiliary member, said stop member being rotatable on said auxiliary member thereby to move the stop member out of said path, the relative lengths of said rule and auxiliary member being such that when said rule abuts said stop member the ends of the rule and of the auxiliary member project an equal distance from said face of said head.

2. A gauge according to claim 1 wherein means are provided to clamp said rule and said auxiliary member to said head in any desired relative positions.

3. A gauge according to claim 1 wherein said stop member is provided with a recess to receive the end of said rule and so locate said rule in abutting relation with said stop member. CHARLES NORMAN McLEOD WORNELL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 7 Date 

